Moving picture coding apparatus

ABSTRACT

When the bit rate of the moving picture data is changed, and the moving picture data is newly produced, to quickly realize the moving picture data production without decoding the moving picture data, and without generating the image quality deterioration due to the motion compensation error. The non-compression moving picture data is an input, quantization means, and rate correction data producing means for producing the rate correction data which is the data to be used at the time of bit rate change, are provided, and the moving picture data having together the rate correction data other than the normal moving picture stream is produced. Thereby, by selecting and replacing the rate correction data whose bit amount is different in the input moving picture data, by adjusting to the objective bit rate, the bit rate is changed and the moving picture data can be quickly produced without decoding the moving picture data.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a bit rate control method for amoving picture coding apparatus to produce the moving picture data inwhich the bit rate is different, from the compression coded movingpicture data.

[0002] Recently, according to the development of the digital signalprocessing engineering, the moving picture data can be compressed andcoded, and the compression coded moving picture data is easily treated.Further, with the development of a computer network, the chance totransmit and receive the compression coded moving picture data throughvarious transmission paths is increased. For example, as a TVbroadcasting station, a large amount of the moving picture datapreviously accumulated, is compression coded and saved, and as a VOD(Video On Demand), at the need of the user, the compression coded movingpicture data can be transmitted onto the transmission path.

[0003] However, in the case where the compression coded moving picturedata is transmitted onto the transmission path, there is sometimes acase where the bit rate which can be transmitted on the transmissionpath is different from the bit rate of the moving picture, and in thecase where the bit rate of the moving picture data is large, when themoving picture is transmitted as it is, there is a problem that thedelay is generated in the reception data, and the moving picture datacan not be reproduced in the real time. Accordingly, in order toreproduce a moving picture in the real time, it is necessary that thebit rate of the moving picture is lowered. Further, it is necessary thatthe bit rate of the moving picture data is adjusted also to the bit rateat which the reception terminal equipment by which the moving picturedata is received, can receive. Further, even in the case where not thewhole frame in the compression coded moving picture data, but only aportion of the frame is quarried out and transmitted, when the bit rateof the quarried out moving picture data exceeds the bit rate at whichthe transmission path can transmit, it is necessary that the processingto lower the bit rate is conducted. As described above, when the movingpicture data is transmitted through various reception terminalequipments and transmission paths, it is necessary that the bit rate ofthe moving picture data is changed by adjusting to various bit rates,and by a time period in which it takes for the processing of the ratecontrol, the delay is generated in the data transmission.

[0004] Further, when the VOD server sends out a plurality of movingpicture data to a plurality of terminal equipments as in the case of theVOD, in proportional to the plurality of number of terminal equipmentsconnected to the VOD server, because the rate control processing becomesheavy, and the burden onto the VOD server becomes large, the number ofterminal equipments which can be simultaneously connected, are limited.That is, the bit rate control method to quickly change the bit rate ofthe moving picture data is absolutely necessary.

[0005] In such the case, as the conventional technique to control thebit rate of the compression coded moving picture data, a method inwhich, initially, the moving picture data is decoded into thenon-compression moving picture data, and coded again, and thereby thebit rate is changed, is well known. However, in this method, because themoving picture data is decoded once, and further, coded again, theburden of this processing is large, and there is a problem that it isdifficult to quickly change the bit rate and produce the moving picturedata.

[0006] Further, as the conventional technique to lighten the re-codingprocessing and to increase the processing speed, a technique disclosedin JP-A-8-23539 is well known. In FIG. 38, the structure of theconventional moving picture coding apparatus is shown. In FIG. 38, amoving picture coding apparatus 5001 is structured by a variable lengthdecoding means 5002 connected to an input means 5006, a re-quantizingmeans 5003, a variable coding means 5004, a buffer memory means 5005,and a buffer occupation amount detecting means 5006, and is connected toan output means 5008.

[0007] Next, an operation of the moving picture coding apparatus will bedescribed. In FIG. 38, the input means 5007 inputs the coded movingpicture data into the variable length decoding means 5002 for each oneframe, and inputs the objective bit rate into the re-quantization means5003. Then, the variable length decoding means 5002 conducts variablelength decoding on the input data, and the quantized DCT (DiscreteCosine Transform) coefficient is found, and outputted to there-quantization means 5003. Then, the re-quantization means 5003re-quantizes the quantized DCT coefficient, and outputs it to thevariable length coding means 5004. In this connection, there-quantization means 5003 compares the bit rate inputted from the inputmeans 5007 to the buffer occupation amount inputted from the bufferoccupation amount detecting means 5006, and the quantization value isset so as to satisfy a predetermined bit rate, and the re-quantizationis conducted. Herein, the quantization value means a value to divide theDCT coefficient in the quantization. Further, the variable length codingmeans 5004 conducts variable length coding on the re-quantized DCTcoefficient, and supplies the moving picture data which is variablelength coded, to the buffer memory means 5005. The buffer memory means5005 outputs the inputted moving picture data from the variable lengthcoding means 5004 to the output means 5008, and outputs the data amountof the moving picture data to the buffer occupation amount detectingmeans 5006. After the buffer occupation amount detecting means 5006 addsthe data amount and detects the buffer occupation amount, the totalamount of the data is outputted to the re-quantization means 5003.

[0008] As described above, when, by using the moving picture codingapparatus 5001, the bit rate is controlled from the compression codedmoving picture data and the moving picture data is newly produced, themoving picture data is produced through the process in which the inputmoving picture data is once variable length decoded, re-quantized, andvariable length coded. That is, because the moving picture data isdecoded and coded again to the inverse quantization processing, thecalculation load is large and it can be said that it is difficult toquickly conduct the rate control. Further, the moving picture data isstructured by a plurality of frames, and because, when the movingpicture data is compression coded, in order to increase the efficiency,generally, the correlation with the preceding frame by one frame in timeis used, and the predictive coding between frames is used. Then, whenthe moving picture data includes the frame on which the predictivecoding between frames is conducted, the problem exists when there-quantization is conducted by using the moving picture codingapparatus.

[0009] When the predictive coding between frames is used, the frame (Pi)on which the re-quantization is conducted in the moving picture codingapparatus 5001, is used for using for the predictive coding betweenframes in the subsequent frame (Pi+1) after one frame in time, and isthe frame which is necessary for addition when the (Pi+1) is decoded.

[0010] Then, when the re-quantization is conducted in the moving picturecoding apparatus 5001, because the re-quantization means changes thequantization value of the input data, the frame (Pi) before there-quatization is conducted, differs from the frame (Pi′) after there-quantization is conducted. Accordingly, when the Pi′ which is changedby the re-quantization, is added to the (Pi+1) on which the inversequantization is conducted, and the (Pi+1) is decoded, because thedifference exists between the Pi to be originally added and Pi′, thedecoded image is deteriorated. Hereinafter, the difference between thePi and Pi′ is called as the motion compensation error. That is, to themoving picture data for which the predictive coding between frames isused, when the moving picture data is produced by using the movingpicture coding apparatus 5001, the image quality deterioration is causeddue to the motion compensation error. Further, in order to prevent theimage quality deterioration, it is necessary that the frame next to theframe on which the re-quantization is conducted, is re-corded includingthe motion compensation, and there is a problem that the processing timeis further increased.

[0011] In the conventional moving picture coding apparatus, when the bitrate of the moving picture data which is previously coded, is changed,and the moving picture data is newly produced, it is necessary to codeagain after the moving picture data is decoded once and re-quantizedagain, and it is difficult to quickly produce the moving picture data.

[0012] When the conventional moving picture coding apparatus is used andthe rate is controlled by conducting the re-quantization, in the nextframe on which the re-quantization is conducted, because the imagequality deterioration due to the motion compensation error is caused, itis difficult to conduct the rate control without causing the imagequality deterioration.

SUMMARY OF THE INVENTION

[0013] An object of the present invention is to solve the abovementioned two problems. That is, the object is that: when the bit rateof the coded moving picture data is changed, and the moving picture datais newly produced, the moving picture data production is quicklyrealized without decoding the moving picture data, and without causingthe image quality deterioration due to the motion compensation error.

[0014] In order to solve the above problems, in a moving picture codingapparatus in which the previously compression coded moving picture datais an input, and the new moving picture data whose bit rate isdifferent, is produced and outputted, the present invention isstructured as follows.

[0015] Firstly, the moving picture data producing apparatus to producethe moving picture data which is an input of the moving picture datacoding apparatus, is provided with a producing means for a ratecorrection data in which the bit amount is different to an area in whichthe bit generation amount in the P frame (predictive coding imagebetween frames) is large, and which can conduct the rate change.

[0016] According to the above description, when the moving picture datais newly produced from the previously coded moving picture data, byadjusting to the objective bit rate, and by selecting and replacing therate correction data whose bit amount is different in the input movingpicture data, the moving picture data production can be quicklyconducted by changing the bit rate without decoding the moving picturedata. Further, by producing the rate correction data in an area in whichthe bit amount is large, the bit rate change can be effectivelyconducted.

[0017] Secondly, the moving picture data producing apparatus whichproduces the moving picture data which is an input of the moving picturecoding apparatus is provided with a means by which the rate correctiondata in which the bit amount is different and the rate change can beconducted, is produced, to an area which is previously determined, andwhose probability to be referred to from the next frame when the motionestimation is conducted, is low, in the P frame (predictive coding imagebetween frames).

[0018] According to this, when the moving picture data is newly producedfrom the previously coded moving data, by selecting and replacing therate correction data whose bit amount in the input moving picture datais different, by adjusting to the objective bit rate, the bit rate ischanged and the moving picture data can be quickly produced withoutdecoding the moving picture data. Further, by producing the ratecorrection data in an area whose probability to be referred to from thenext frame, is low, the lowering of the predictive coding efficiency dueto the influence of the search range limitation of the motion estimationcan be reduced.

[0019] Thirdly, the moving picture data producing apparatus to producethe moving picture data which is an input of the moving picture codingapparatus, is provided with a means f or producing the rate correctiondata whose bit amount is different, in the P frame, and provided withthe motion compensation means for conducting the motion compensationwithout referring to from the area having the rate correction data, whenthe movement of the next frame is forecast.

[0020] According to this, when the moving picture data is newly producedfrom the previously coded moving picture data, even when the movingpicture data is produced by selecting the rate correction data whose bitamount is different, in the input moving picture data, because the areais not subject to the motion estimation, the generation of the motioncompensation error due to the replacement of the data can be prevented.

[0021] Fourthly, the moving picture data producing apparatus to producethe moving picture data which is the input data of the moving picturecoding apparatus, is provided with a means for producing the ratecorrection data whose bit amount is different, and which can change thebit rate, to an area in which the referred degree from the next framewhen the movement is forecast, is low, in the P frame.

[0022] According to the above description, when the moving picture dataproducing apparatus produces the moving picture data, the moving picturedata can be produced without lowering the coding efficiency of thepredictive coding between frames.

[0023] Fifthly, the moving picture data producing apparatus to producethe moving picture data which is the input data of the moving picturecoding apparatus is provided with a means for producing the ratecorrection data, by removing the high frequency component of theoriginal image, and by conducting the predictive coding between frames,to each P frame of the moving picture data.

[0024] According to the above description, when the moving picture datais newly produced without decoding the previously coded moving picturedata, corresponding to the objective bit rate, by selecting each area ofthe rate correction data coded by removing the high frequency component,the fine bit rate control can be quickly conducted.

[0025] Sixthly, the moving picture data producing apparatus to producethe moving picture data which is the input data of the moving picturecoding apparatus is provided with a means for producing the areainformation showing an area of the rear portion at which the bit can bedeleted, in each area, as the rate correction data.

[0026] According to the above description, in the moving picture codingapparatus which produces the new moving picture data from the codedmoving picture data, by adjusting to the objective bit rate, when eacharea of the input moving picture data is selected, and the rear portionbit is deleted, the bit rate control can be quickly conducted.

[0027] Seventhly, the moving picture data producing apparatus to producethe moving picture data which is the input data of the moving picturecoding apparatus is provided with a means for producing the I framewhose bit amount is different, as the rate correction data, to each Pframe.

[0028] According to this, in the moving picture coding apparatus whichproduces the new moving picture data from the previously coded movingpicture data, by adjusting to the objective bit rate, and by replacing Pframe of the input moving picture data with the I frame whose bit amountis different which is the rate correction data, the bit rate control canbe quickly conducted without decoding the input moving picture data.

[0029] Eighthly, in the case where the moving picture data producingapparatus to produce the moving picture data which is the input of themoving picture coding apparatus is provided with a means for determiningthe quarry out area in each frame, and for producing the rate correctiondata by which the rate correction is possible, for at least an area morethan one in each quarry out area in the frames, and a motioncompensation means for inhibiting the motion estimation outside the areahaving the rate correction data in the preceding frame at the time ofmotion compensation and the quarry out area, when one portion in theframe is quarried out from the previously coded moving picture data andthe moving picture data is newly produced, corresponding to theobjective bit rate, by selecting the data whose bit amount is different,the bit rate is controlled and the moving picture data can be quicklyproduced without decoding the moving picture data. Further, because themotion estimation to the outside of the quarried out area is notconducted, even by using only the quarried out area of a portion of theframe, the decoding can be conducted without generating the motioncompensation error.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030]FIG. 1 is a block diagram showing the structure of a movingpicture data producing apparatus in the first embodiment of the presentinvention;

[0031]FIG. 2 is a block diagram showing the structure of a movingpicture coding apparatus in the first embodiment of the presentinvention;

[0032]FIG. 3 is a block diagram showing the structure of the movingpicture data producing apparatus in the second embodiment of the presentinvention;

[0033]FIG. 4 is a block diagram showing the structure of the movingpicture data producing apparatus in the third embodiment of the presentinvention;

[0034]FIG. 5 is a block diagram showing the structure of the movingpicture data producing apparatus in the fourth embodiment of the presentinvention;

[0035]FIG. 6 is a block diagram showing the structure of the movingpicture data producing apparatus in the fifth embodiment of the presentinvention;

[0036]FIG. 7 is a block diagram showing the structure of the movingpicture coding apparatus in the fifth embodiment of the presentinvention;

[0037]FIG. 8 is a block diagram showing the structure of the movingpicture data producing apparatus in the sixth embodiment of the presentinvention;

[0038]FIG. 9 is a block diagram showing the structure of the movingpicture coding apparatus in the sixth embodiment of the presentinvention;

[0039]FIG. 10 is a view showing an example of an area dividing theinside of the frame in the first embodiment of the present invention;

[0040]FIG. 11 is a view showing a compression frame buffer structure inthe first embodiment of the present invention;

[0041]FIG. 12 is a view showing the rate correction area data in thefirst embodiment of the present invention;

[0042]FIG. 13 is a view showing the compression frame data in the firstembodiment of the present invention;

[0043]FIG. 14 is a view showing the moving picture data structure in thefirst embodiment of the present invention;

[0044]FIG. 15 is a view showing the data structure of the ratecorrection data in the first embodiment of the present invention;

[0045]FIG. 16 is a view showing the content of the rate correction datain the first embodiment of the present invention;

[0046]FIG. 17 is a view showing the rate correction data headerstructure in the first embodiment of the present invention;

[0047]FIG. 18 is a view showing the referred area data in the thirdembodiment of the present invention;

[0048]FIG. 19 is a view showing the compression frame data in the fourthembodiment of the present invention;

[0049]FIG. 20 is a view showing the rate correction data headerstructure in the fourth embodiment of the present invention;

[0050]FIG. 21 is a view showing the structure of the moving picturecoding apparatus in the fourth embodiment of the present invention;

[0051]FIG. 22 is a view showing a flow of a rate control method in thefourth embodiment of the present invention;

[0052]FIG. 23 is a view showing the structure of a Video Packet in thefifth embodiment of the present invention;

[0053]FIG. 24 is a view showing the Video Packet termination datastructure in the fifth embodiment of the present invention;

[0054]FIG. 25 is a view showing the rate correction data structure andthe rate correction data header structure in the fifth embodiment of thepresent invention;

[0055]FIG. 26 is a view showing the data content of the rate correctiondata in the fifth embodiment of the present invention;

[0056]FIG. 27 is a view showing the rate correction data structure andthe rate correction data header structure in the sixth embodiment of thepresent invention;

[0057]FIG. 28 is a view showing the data content of the rate correctiondata in the sixth embodiment of the present invention;

[0058]FIG. 29 is a view showing the structure of the moving picture dataproducing apparatus in the seventh embodiment of the present invention;

[0059]FIG. 30 is a view showing an example of a quarry out area in the 1frame in the seventh embodiment of the present invention.;

[0060]FIG. 31 is a view showing the rate correction area data structurein the seventh embodiment of the present invention;

[0061]FIG. 32 is a view showing the compression frame data structure inthe seventh embodiment of the present invention;

[0062]FIG. 33 is a view showing the rate correction data structure inthe seventh embodiment of the present invention;

[0063]FIG. 34 is a view the rate correction data header structure in theseventh embodiment of the present invention;

[0064]FIG. 35 is a view showing the structure of the moving picturecoding apparatus in the seventh embodiment of the present invention;

[0065]FIG. 36 is a view showing the Video Packet structure data in thefifth embodiment of the present invention;

[0066]FIG. 37 is a view showing the structure of I frame coding means inthe sixth embodiment of the present invention; and

[0067]FIG. 38 is a block diagram showing the structure of the movingpicture coding apparatus which is the conventional technology.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0068] By using FIG. 1 to FIG. 37, embodiments of the present inventionwill be described below. In this connection, the present invention isnot limited to these embodiments, but in the range not departing fromthe spirit of the invention, the present invention can be conducted invarious modes.

[0069] Embodiment 1

[0070] In the first embodiment, a moving picture coding apparatus bywhich the rate control is conducted without decoding by using thepreviously compression coded moving picture data, and the moving picturedata is newly produced, and its method will be described below.

[0071] Initially, the moving picture data producing apparatus whichpreviously produces the moving picture data which is an input of themoving picture coding apparatus, will be described below.

[0072] In FIG. 1, the structure of the moving picture data producingapparatus to previously produce the moving picture data having the datastructure to quickly conduct the rate control, is shown.

[0073] In FIG. 1, a moving picture data producing apparatus 101 isprovided with: a frame input means 117 connected to an input means 116;motion compensation means 102; DCT conversion means 103; quantizingmeans 104; variable length coding means 105; inverse quantizing means toconduct the decoding; inverse DCT conversion means 107; and a framememory 108 to store the decoded frame, and is provided with: a maximumbit amount area detecting means 110 which is connected to the variablelength coding means 105 and successively detects an area having themaximum bit amount; reference inhibition area memory means 109;compression frame buffer 112 connected to the DCT conversion means 103;quantization means 111 which is connected to the compression framebuffer 112 and conducts the quantization; and variable length codingmeans 113, and is provided with: a compression frame data combinationmeans 114 which is connected to the variable length coding means 105,reference inhibition area memory means 109 and variable length codingmeans 113, and combines with the moving picture data, and has thestructure to be connected to an output means 115.

[0074] The operation of the thus structured moving picture dataproducing apparatus will be described below.

[0075] Initially, the input means 116 inputs the non-compression imageinto the frame input means 117. When the frame input means 117 receivesthe frame coding end signal inputted from the compression frame datacombination means 114, the non-compression one frame data inputs intothe motion compensation means 102. However, when the first frame data isinputted, it is independent from the frame coding end signal, andsimultaneously when the data is inputted from the input means 116, thenon-compression frame data is inputted into the motion compensationmeans 102.

[0076] Then, when the motion compensation means 102 conducts thepredictive coding between frames on the non-compression frame datainputted from the frame input means 117, after the area whosecorrelation is high in the preceding frame by one frame inputted fromthe frame memory 108 is detected, it conducts the subtraction, andoutputs the subtracted frame data to the DCT conversion means 103. Inthis case, the motion compensation means 102 does not conduct the motiondetection from the reference inhibition area of the preceding frame byone frame inputted from the reference inhibition area memory means 109.Further, it does not conduct the motion compensation on the data onwhich the coding in the frame is conducted, and the input data isoutputted to the DCT conversion means as it is.

[0077] The DCT conversion means 103 conducts the DCT conversion on theframe data which is inputted by the motion compensation means 102, andoutputs the DCT coefficient to the quantization means 104 and thecompression frame buffer 112.

[0078] In FIG. 10, an example of the dividing method of an area in theframe is shown. Herein, the area shown in FIG. 10 is structured by anarbitrary number of macro-blocks (for example, 16×16 pixels), and anyshape maybe allowable, and is not limited to the shape shown in FIG. 10.Further, the structure of the compression frame buffer is shown in FIG.11. The compression frame buffer respectively continuously accommodatesthe quantization amount and the DCT coefficient, corresponding to eacharea in FIG. 10.

[0079] The quantization means 104 quantizes the DCT coefficient obtainedby the DCT conversion means 103 for each area shown in FIG. 10, and thequantized DCT coefficient is outputted to the inverse quantization means106 and the variable length coding means 105, and the quantization valueused for the quantization is outputted to the compression frame buffer112. The compression frame buffer 112 makes the DCT coefficient for oneframe inputted by the DCT conversion means 103 for each area shown inFIG. 10, and the quantization value inputted by the quantization means104 respectively correspond to each other as shown in FIG. 11, andstores them.

[0080] The variable length coding means 105 conducts the variable lengthcoding on the quantized DCT coefficient, and outputs it to the maximumbit amount area detecting means 110 and the compression frame datacombination means 114. Herein, the data which is coded by the variablelength coding means 105 is called the normal frame data.

[0081] Further, the inverse quantization means 106 conducts the inversequantization on the DCT coefficient quantized by the quantization means104, and outputs it to the inverse DCT conversion means 107. The inverseDCT conversion means 107 conducts the inverse DCT conversion on the DCTcoefficient obtained in the inverse quantization means 106, and outputsit to the motion compensation means 102. The motion compensation means102 decodes the frame by using the inverse DCT converted coefficient andthe decoding frame which is the preceding frame by one frame inputted bythe frame memory, and renews the decoding frame of the frame memory.However, for the I frame, the inverse DCT converted frame is stored inthe frame memory as it is.

[0082] As described above, in the variable length coding means 105, whenthe coding of one frame is completed, the maximum bit amount detectingmeans 110 detects a predetermined number of areas in order of areahaving the larger bit amount from the area including the maximum bitamount, in the frame coded by the variable length coding means 105, andoutputs the rate correction area data showing the detected areas to thereference inhibition are a memory means 109 and the compression framebuffer 112. In FIG. 12, an example of the rate correction area data isshown. In FIG. 12, a black area shows the selected areas by the framemaximum bit area detecting means, and this area is defined as thereference inhibition area.

[0083] The reference inhibition area memory means 109 outputs thecorrection area data showing the detected area by the maximum bit amountarea detecting means 110 to the motion compensation means 102 and themoving picture data combination means 114. Then, the compression framebuffer 112 cuts out the DCT coefficient and the quantization value ofthe area corresponding from the inside of the compression frame buffer,to the reference inhibition area of the correction area data inputted bythe maximum bit amount area detecting means 110, and outputs them to thequantization means 111. The quantization means 111 conducts thequantization by using a plurality of quantization value s before andafter the quantization value s inputted from the compression framebuffer 112, on the DCT coefficient inputted from the compression framebuffer 112, and outputs it to the variable length coding means 113.

[0084] In the quantization means 111, when the quantization is conductedby using the different quantization value, the data whose bit amount isdifferent can be produced.

[0085] For example, when the quantization is conducted by thequantization value Q=2, on the input stream in which an image plane sizeis CIF (352×288) and the frame rate is 30 fps, and the MPEG 4 stream ismade, the bit rate is about 1.6 Mbps, and like as at Q=6, about 384kbps, at Q=16, about 128 kbps, and at Q=30, about 56 kbps, the datawhose bit rate is different, can be produced corresponding to thequantization value Q.

[0086] The variable length coding means 113 conducts variable lengthcoding on the DCT coefficient quantized by the quantization means 111,and produces the correction data, and produces the rate correction datahaving the number of areas, the number of correction data of each area,the area number and the data size of respective correction data as theheader information, and outputs it to the compression frame datacombination means 114. Herein, the data produced by the variable lengthcoding means 113 is defined as the rate correction data. In FIG. 15, thestructure of the rate correction data is shown, and the content of therate correction data is shown in FIG. 16. Further, the structure of therate correction data header is shown in FIG. 17. In FIG. 17, the ratecorrection data header 1502 has a structure in which the number in eacharea of the correction data whose bit amount is different, which isproduced by changing the number of areas and the quantization value, andthe area number and the bit amount of respective correction data arestored as the fixed length data. Herein, the order of areas is definedas the order in which the bit amount is larger. Then, in FIG. 15, therate correction data has the structure in which the correction data isstored succeeding to the rate correction data header 1502 in order ofthe area in which the bit amount of the correction data is larger. Thestructure of the compression frame data is shown in FIG. 13. In FIG. 13,the compression frame data has a structure in which the rate correctionarea data and the rate correction data are successively stored after thenormal frame data.

[0087] The compression frame data combination means 114 stores thenormal frame data inputted by the variable length coding means 105, thecorrection area data inputted by the reference inhibition area memorymeans 109, and the rate correction data inputted by the variable lengthcoding means 113 in order as shown in FIG. 13, and outputs them as thecompression frame data 1301 to the output means 115, and outputs theframe coding end signal showing that the coding of one frame iscompleted, to the frame input means 117. The structure of the movingpicture data is shown in FIG. 14. In FIG. 14, the moving picture data1401 has a structure in which the compression frame data is successivelystored.

[0088] Thus coded moving picture data 1401 has a structure in which, foreach frame, the normal frame data, the rate correction area data showingthe area in which the rate correction data exists, and the ratecorrection data whose bit amount is different, are arranged in order.Then, the area having the rate correction data, that is, the referenceinhibition area inhibits the reference from the next frame at the timeof motion estimation, and because it is in the condition that the motionestimation is not received from the next frame, even when the data ofthis area is replaced with the rate correction data and the bit ratechange is conducted, the motion compensation error is not generated whenthe next frame is decoded.

[0089] Next, the structure of the moving picture coding apparatus bywhich the moving picture data coded by the moving picture codingapparatus shown in FIG. 1 is used as the input data, and the ratecontrol is conducted without decoding the input data, and the ratechanged moving picture data is newly produced, is shown in FIG. 2.

[0090] In FIG. 2, the moving picture coding apparatus 201 has a dataseparation means 207 connected to an input means 202, bit amountcalculation means 203, rate correction data selection means 204, bitrate control means 205 and moving picture combination means 208, and hasa structure in which it is connected to an output means 206.

[0091] The operation of thus structured moving picture coding apparatuswill be described below. In FIG. 2, the input means 202 inputs thecompression coded moving picture data 1301 and the objective bit ratewhich is determined by the user, to the data separation means 207. Whenthe data is inputted by the input means 292, the data separation means207 inputs the objective bit frame by each one frame to the bit ratecontrol means 205, and further, takes out the data in order from theleading data of the inputted moving picture data, and inputs the normalframe data for each one frame to the bit amount calculation means 203,and inputs the rate correction area data and the rate correction datafor each one frame to the rate correction data selection means 204.Herein, when the input means 202 inputs the frames other than the firstone frame of the moving picture data, after the frame coding end signalis received from the rate correction data selection means 204, itconducts the respective data input.

[0092] The bit amount calculation means 203 calculates the bit amount ofthe inputted normal frame data, and outputs the bit amount to the bitrate control means 205, and outputs the normal frame data to the ratecorrection data selection means.

[0093] The bit rate control means 205 compares the objective bit rateinputted from the inputted means 202 to the current bit amount inputtedfrom the bit amount detecting means 203, and the insufficient bit amountnecessary for satisfying the objective bit rate, or sufficient bitamount is obtained, and is outputted to the rate correction dataselection means 204.

[0094] The rate correction data selection means receives the bit amountwhich is a bit rate error, inputted by the bit rate control means 205,and in order to satisfy the objective bit rate, to the area shown by therate correction area data inputted by the data separation means 207, itcompares the bit amount of the area in the normal frame data to the bitamount of the plurality of correction data stored in the rate correctiondata header 1502, and when the data is replaced, the correction data bywhich the bit rate error becomes small, is selected in order of storedareas, and by replacing the data in the normal frame data with selectedcorrection data, the bit amount is changed. Further, when the bit amounterror is large, the correction data is selected from the next area, andby replacing the data, the bit amount is changed. By repeating the aboveprocessing, the moving picture data in which the bit amount error ismade minimum, is outputted to the moving picture data combination means208, and one frame coding end signal is outputted to the data separationmeans 207.

[0095] The moving picture data combination means 208 connects the framedata inputted for each frame from the rate correction data selectionmeans 204 in order, and produces the moving picture data and outputs tothe output means 206.

[0096] Herein, when the area is selected by the rate correction dataselection means 204 and the data is replaced corresponding to the bitamount, there is a problem that the motion compensation error is causedby the replacement of the data which is referred to as the motioncompensation after I frames in the conventional method, and the imagequality deterioration is caused, however in the present invention,because the reference to the area having the rate correction data isinhibited by the reference inhibition area memory means 109 in themoving picture data producing apparatus in FIG. 1, even when thecorrection data is selected and replaced, the motion compensation erroris not caused. Accordingly, the rate control can be quickly conducted byselecting the correction data without decoding the moving picture dataand without causing the image quality deterioration due to the motioncompensation error.

[0097] Further, in the present embodiment, the number of areas detectedby the maximum bit area detecting means 110 is determined by the usercorresponding to, to what % the bit rate of the input data can bechanged, and the larger the number of areas is, the larger the range ofthe bit rate change is. However, when the number of areas is increased,because the reference area used for the motion estimation becomesnarrow, the coding efficiency is lowered. In order to solve the problem,the maximum bit area detecting means 110 detects the area from the areahaving the maximum bit in the order in which the bit amount is larger.It is because the compression coded data does not always have a uniformbit amount in the frame, and there are cases where the area having thelarger bit amount exists locally, and when the correction data isprovided to such the area in which the bit amount is large, the bit ratechange becomes easy, and the reference inhibition area can be reduced.

[0098] Further, the number of rate correction data of each area selectedby the maximum bit area detecting means 110 and the value of respectivequantization value also contribute to the width of the bit rate change.For example, when the quantization of the normal frame data is conductedat Q=6, the bit rate is about 384 kbps, and as the area having the ratecorrection data, a plurality of areas having the data amount of about ¾of the whole in total are selected from the areas whose bit amount islarge. When the deviation of the bit is considered, an area of the areasis lower than ¾. For these areas, by using the quantization values Q=2,Q=30, two kinds of rate correction data of about 1.6 Mbps, and about 56kbps are produced. Whole data size including the rate correction data isabout 1.6 Mbps. When the moving picture data including the ratecorrection data is combined with the rate correction data, the bit ratechange can be arbitrarily conducted in the range of about 1.5 Mbps toabout 64 kbps, and the moving picture data matched with bit rates ofvarious transmission paths can be produced.

[0099] Further, the calculation cost relating to the rate change is low,and a plurality of streams in which bit rates are different, can bequickly produced. Further, when the stream whose bit rate is differentis prepared from the initial time, the bit rate is fixed and its datasize becomes large. Comparing to that case, in the present embodiment,it is enough when the data size is slightly larger than the maximum bitrate which is presumed.

[0100] As described above, in the present embodiment, the motioncompensation means which does not conduct the motion compensation fromthe reference inhibition area, and the moving picture data producingapparatus which produces the moving picture data having together therate correction data, and the area selection means which selects therate correction data corresponding to the bit rate, are provided,thereby, the apparatus can quickly conduct the rate control withoutdecoding the moving picture data, and without causing the image qualitydeterioration due to the motion compensation error, and can quicklyproduce a plurality of streams in which the bit rate is different,thereby, its practical effect is large.

[0101] Embodiment 2

[0102] In the second embodiment, an apparatus in which the rate controlis conducted from the previously coded moving picture data without beingdecoded, and the moving picture data is newly produced, and which ischaracterized in that, as the area selection method to produce the ratecorrection data, the known area which is hardly referred to at the timeof motion estimation, is used, will be described below.

[0103] In the present embodiment, the moving picture coding apparatus bywhich the rate change is conducted from the previously coded movingpicture data, and moving picture data is newly produced, is the same asin Embodiment 1.

[0104] A moving picture data producing apparatus by which the movingpicture data which is an input of the moving picture coding apparatus toquickly conduct the rate control, is previously produced, will bedescribed below.

[0105] In FIG. 3, the structure of the moving picture data producingapparatus by which the moving picture data having the data structure toquickly conduct the rate control is produced, is shown.

[0106] In FIG. 3, the moving picture data producing apparatus 301 isprovided with: a frame input means 117 connected to an input means 116;motion compensation means; DCT conversion means 103; quantization means104; variable length coding means 105; inverse quantization means 106for conducting the decoding; inverse DCT conversion means 107; and framememory 108 for storing the decoded frame, and the apparatus is connectedto the variable length coding means 105, and is provided with: the ratecorrection area selection means 310 for selecting the area producing therate correction data; reference inhibition area memory means 109;compression frame buffer 112 to connect to the DCT conversion means 103;quantization means 111 to connect to the compression frame buffer and toconduct the quantization; and variable length coding means 113, and isconnected to the variable length coding means 105, reference inhibitionarea memory means 109, and variable length coding means 113, and isprovided with a compression frame data combination means 114 to combinethe moving picture data, and has a structure which is connected to anoutput means 115.

[0107] Operations of thus structured moving picture coding apparatuswill be described below.

[0108] In FIG. 3, operations other than the rate correction selectionmeans 310 are entirely the same as in Embodiment 1. In FIG. 3, thevariable length coding means 105 conducts the variable length coding onthe quantized DCT coefficient inputted from the quantization means 104in the same manner as in Embodiment 1, and outputs it to the ratecorrection area selection means 310 and the compression frame datacombination means 114. Herein, the data coded by the variable lengthcoding means 105 is called the normal frame data.

[0109] As described above, when the coding of the normal frame data iscompleted, the rate correction data area selection means 310 selects thearea for the rate correction from the frame coded in the variable lengthcoding means 105, and outputs the rate correction area data 1201 showingthe selected area as shown in FIG. 12, to the reference inhibition areamemory means 109 and the compression frame buffer 112. Herein, the areaselected as the rate correction area is an area to which the probabilityto be referred from the next frame at the time of the motion estimation,is low, for example, such as a rim portion of the frame, and is definedas the known area which is previously stored in the rate correction dataarea selection means 310.

[0110] In the present embodiment, it is inhibited that the area for ratecorrection is referred to at the time of motion estimation, and byinhibiting the reference, because the search area at the time of motionestimation is small, there is a possibility that the predictive codingefficiency is lowered. Therefore, the area which is hardly referred toat the time of motion estimation, is defined in such a manner that it isselected as the rate correction area. Thereby, even when the search areaat the time of motion estimation becomes small, because the area has thesmall probability to be originally referred to, the practical searcharea is not small, that is, the predictive coding efficiency can beprevented from lowering. Operations after the compression frame buffer112 are the same as in Embodiment 1.

[0111] Thus coded moving picture data has the structure having, to eachframe, the compression coded normal frame data, rate correction areadata showing the area in which the rate correction data exists, and ratecorrection data including a plurality of correction data whose bitamount is different, and the area having the rate correction data is inthe condition that it is not referred to at the time of motionestimation from the next frame.

[0112] As described above, when the coded moving picture data is aninput, and by using the moving picture coding apparatus shown in FIG. 2,in the same manner as in Embodiment 1, the rate correction datacorresponding to the objective bit rate is selected, and it is replacedwith the data in the normal frame data, by producing the new movingpicture data, the rate control can be quickly conducted without decodingthe data.

[0113] Further, the area to produce the rate correction data is definedas the known area, such as the rim portion of the frame which is hardlyreferred to at the time of motion estimation, and the size of the areacan be determined by the user corresponding to the range of the changeof the bit rate. Further, the number of the rate correction data and thequantization value in each area also contribute to the width of the bitrate change.

[0114] For example, when the quantization of the normal frame data(size: CIF, frame rate 30 fps) is conducted at Q=24, the bit ratebecomes about 100 kbps. To this. the area of the size of total of about40% at the ratio of the area of the frame, in which the motionestimation is hardly conducted, is defined as the rate correction dataarea, and on respective area data, the quantization is conducted at thetwo quantization values Q=16 and 31, and the rate correction data havingthe bit rate corresponding to about 128 kbps, and about 32 kbps areproduced. With the moving picture data having these rate correctiondata, when the rate correction data is combined, the bit rate can bearbitrarily changed between about 128 kbps and about 64 kbps, and themoving picture data corresponding to the fluctuation of the band of thetransmission path can be quickly produced. Further, the calculation costaccording to the bit rate change is low, and a plurality of movingpicture data whose bit rate is different, can be quickly produced.

[0115] In the present embodiment, the range of the bit rate change issmaller as compared to Embodiment 1, but the present invention ischaracterized in that, because the area which is set as the referenceinhibition area, has the character which is hardly forecast, thelowering of the coding efficiency can be prevented. Further, the datasize of the moving picture data is about 128 kbps, and almost equal tothe maximum value of the bit rate change.

[0116] As described above, in the present embodiment, when the movingpicture data producing apparatus in which a plurality of rate correctiondata whose bit amount are different, are produced, to the area to whichthe probability to be referred at the time of motion estimation is low,and the control means which is matched with the objective bit rate, andselects the rate correction data, and conducts the rate control, areprovided, because the predictive coding efficiency at the time of motionestimation is not lowered, and the rate control can be quickly conductedwithout causing the image quality deterioration due to the motioncompensation error, a plurality of moving picture data whose bit ratesare different, can be quickly produced, thereby, its practical effect islarge.

[0117] Embodiment 3

[0118] In the third embodiment, the moving picture data producingapparatus in which the rate control is conducted from the previouslycoded moving picture data without being decoded, and the moving picturedata is newly produced, wherein the apparatus has, to the moving picturedata, by using the referred degree at the time of the motion estimation,a means for selecting the rate correction area to produce a plurality ofdata in which the bit amount is different, will be described below.

[0119] Further, in the present embodiment, the moving picture codingapparatus in which the rate control is conducted from the previouslycoded moving picture data, and the moving picture data is newlyproduced, is entirely the same as in Embodiment 1.

[0120] The structure of the moving picture data producing apparatus isshown in FIG. 4. In FIG. 4, a moving picture data producing apparatus401 has: a frame input means 117 connected to an input means 116; motioncompensation means 402; DCT conversion means 103; quantization means104; variable length coding means 105; inverse quantization means 105for decoding; inverse DCT conversion means 107; and frame memory 108 forstoring the decoded frame, and a referred area memory means 410connected to a motion compensation means 402; and a rate correction areaselection means 412, and a compression frame buffer 112 connected to aDCT conversion means 404; quantization means 111; and variable lengthcoding means 113, and a rate correction area selection means 412;compression frame combination means 414 connected to the variable lengthcoding means 113 and variable length coding means 105, and has astructure in which these means are connected to the output means 115.

[0121] Operations of thus structured moving picture producing apparatuswill be described below. In the moving picture coding apparatus 401, theinput means 116, frame input means 117, DCT conversion means 103,quantization means 104, variable length coding means 105, inversequantization means 106, inverse DCT conversion means 107, and framememory 108 produce the normal frame data in entirely the same manner asin Embodiment 1. In this connection, the variable length coding means405 outputs the frame coding end signal to the frame input means 117when the normal frame data producing is completed. In this manner, whenthe normal frame data for one frame is produced, the frame input means117 outputs the next non-compression frame to the motion compensationmeans 402.

[0122] The motion compensation means 402 does not conduct the motioncompensation on the I frame, and outputs to the DCT conversion means103, and in the case of other than I frame, the motion compensation isconducted by using the preceding frame by 1 frame and the frame inputtedby the frame input means 117. Further, in the preceding frame by 1frame, the area information which is referred to at the time of motionestimation, is outputted to the referred area memory means 410.

[0123] The referred area data is shown in FIG. 18. The referred areadata is the data in which the referred degree of each area is stored. Inthe referred area data, the referred degree of each area means that, inpixels in the area, total pixel number which is referred to at the timeof motion estimation from the next frame, is shown, and in FIG. 18, itis defined that the thicker the color of the area is, the higher thereferred degree is.

[0124] The referred area memory means 410 stores the referred areainputted from the motion compensation means 403, and outputs thereferred area data showing the referred area to the rate correction areaselection means 412.

[0125] The rate correction area selection means 412 selects, in theinputted referred area data, a predetermined number of areas in theorder from the area in which the referred area is low, as the ratecorrection data area. Further, the selected area is the rate correctionarea in the preceding frame by one frame to the frame currently inputtedby the frame input means, and outputs the rate correction area data 1201showing the selected rate correction area to the compression framebuffer 112 and the moving picture data combination means 414. Further,the operation of the compression frame buffer 112, quantization means111, and variable length coding means 113 is the same as in Embodiment1.

[0126] The compression frame combination means 414 combines the normalframe data inputted from the variable coding means 405, the ratecorrection area data inputted from the rate correction area selectionmeans 412, and the rate correction data inputted from the variablelength coding means 113 as shown in FIG. 13, and outputs it to theoutput means 115. In the present embodiment, because it is not conductedthat the reference inhibition area is set at the time of motionestimation and the search area is limited, as shown in Embodiments 1 and2, the search area is not limited, and the predictive coding effect canbe more enhanced than in Embodiments 1 and 2.

[0127] By using the coded moving picture data as an input as describedabove, and the moving picture coding apparatus in FIG. 2, when the newmoving picture data is produced in the same manner as in Embodiment 1,the rate control can be quickly conducted without decoding the data.Further, because, as the area having the rate correction data, the areato which the referred degree is low at the time of motion estimation, isselected, even when the rate correction data is selected at the time ofthe rate control, the motion compensation error is not caused. Further,the number of area to be selected in the order from the area in whichthe referred degree is lower, can be determined by the usercorresponding to the range of the bit rate change. Further, the numberof rate correction data and the quantization value in respective areasalso contribute to the width of the bit rate change.

[0128] For example, when the quantization of the normal frame data(size: CIF, frame rate 30 fps) is conducted at Q=24, the bit rate isabout 100 kbps. In contrast to this, the area in which the referreddegree is low and the size is the total of about 30% in the area ratioof the frame, is defined as the rate correction data area, and torespective areas, the quantization is conducted at two quantizationvalues of Q=16 and 32, and the rate correction data having the bit ratecorresponding to about 128 kbps and about 32 kbps is produced. With themoving picture data having this rate correction data, when the ratecorrection data is combined, the bit rate can be arbitrarily changedbetween about 128 and about 64 kbps, the moving picture datacorresponding to the fluctuation of the band of the transmission pathcan be quickly produced. Further, the calculation cost according to thebit rate change is low, and a plurality of moving picture data whose bitrate are different, can be quickly produced. Further, the data size ofthe moving picture data is about 128 kbps, and it is almost equal to themaximum value of the bit rate change. In this example, the range of thebit rate change is smaller than in Embodiment 1, however, because thereference inhibition area is not provided, the lowering of the codingefficiency can be prevented, and because the area having the ratecorrection data is an area to which the practical referred degree islow, the generation of the motion compensation error which accompaniesthe replacement of the data can be suppressed to small.

[0129] As described above, in the present embodiment, the moving picturedata structure having the rate correction data to the area to which thereferred degree is low at the time of motion estimation, and the movingpicture data producing apparatus which selects the rate correction dataand changes the bit rate, are provided, and thereby, because thepredictive coding efficiency of the motion estimation is not lowered andthe motion compensation error generated when the rate correction data isused is lowered, and the rate control can be quickly conducted, aplurality of moving picture data whose bit rates are different, can bequickly produced, and its practical effect is large.

[0130] Embodiment 4

[0131] In the fourth embodiment, in an apparatus by which the previouslycoded moving picture data is not decoded, and the rate control isconducted, and the new moving picture data is produced, the apparatuscharacterized in that the input moving picture data has the ratecorrection data whose bit amount is slightly different, on the entireframe, will be described below.

[0132] In FIG. 5, the structure of the moving pictured at a producingapparatus by which the coding is previously conducted for the input dataof the moving picture coding apparatus to conduct the rate control, isshown. In FIG. 5, the moving data producing apparatus 501 is providedwith: the frame input means 117 connected to the input means 116; motioncompensation means 102; DCT conversion means 103; quantization means104; and variable length coding means 105, and is provided with theinverse quantization means 106 for conducting the decoding; inverse DCTconversion means 107; and frame memory 108. Further, the moving picturecoding apparatus 501 is provided with: a low pass filter 503 connectedto the frame input means 117; motion compensation means 102 connected tothe low pass filter 503; DCT conversion means 103; quantization means104; and variable length coding means 106, and is provided with: theinverse quantisation means 106 which is connected to the quantizationmeans 104 and conducts the decoding; inverse DCT conversion means 107;and frame memory 108. Further, the moving picture data producingapparatus 501 is structured in such a manner that it is connected to thevariable length coding means 105, the compression frame data combinationmeans 504 connected to the variable length coding means 105, and outputmeans 115.

[0133] The operation of thus structured moving picture data producingapparatus will be described below. In the moving picture codingapparatus 501, teh frame input means 117, motion compensation means 102,DCT conversion means 103, quantization means 104, variable length codingmeans 105, inverse quantization means 106, invesr DCT conversion means107, and frame memory 108 are blocks for producing the normal frame datain the same manner as in Embodiment 1.

[0134] Further, in FIG. 5, the low pass filter 503 causes thenon-compression frame to pass through the low pass filter, reduces thehigh frequency information of the input frame, and outputs it to themotion compensation means 102. Hereinafter, by using the DCT conversionmeans 103, quantization means 104, variable length coding means 506,inverse quantization means 106, inverse DCT conversion means 107, andframe memory 108, in the same manner as in the normal frame dataproduction, by using the same quantization value, the frame data isproduced. In this connection, the frame data produced herein is the dataproduced in such a manner that the data in which the high frequency ofthe input frame is reduced by the low pass filter 503, is coded, and isthe data in which its bit amount is fewer than the normal frame data,and has the structure in which it has the correction data to the wholearea in 1 frame shown in FIG. 10, and this data is called the ratecorrection data. The variable length coding means 506 calculates, to therate correction data, the rate correction data header as shown in FIG.20, and outputs the rate correction data and the rate correction dataheader to the moving picture combination means 20. The rate correctiondata header has the structure having the number of areas in the ratecorrection data 1 frame, and the bit amount in each area.

[0135] The compression frame data combination means 504 combines thenormal frame data inputted from the variable length coding means 105,rate correction data header inputted from the variable length codingmeans 506, and rate correction data as shown in FIG. 19, and outputs itto the output means 115.

[0136] As described above, in the present embodiment, the structurehaving the rate correction data is applied to all areas of 1 frame, andrespective data amounts of the normal frame outputted from the variablelength coding means 105, and the rate correction data outputted from thevariable length coding means 106, are slightly different, by reducingthe high frequency component of the non-compression frame.

[0137] The structure of the moving picture coding apparatus in which themoving picture data coded as described above is an input, and the ratecontrol is conducted without decoding the data, and the moving picturedata is newly produced, is shown in FIG. 21. In FIG. 21, the movingpicture coding apparatus 2101 is provided with: the data separationmeans 207 connected to the input means 202; bit amount calculation means203; rate correction data selection means 2104; bit rate control means205; and moving picture data combination means 208, and the apparatushas the structure in which these are connected to the output means 206.

[0138] The operation of thus structured moving picture coding apparatus2101 will be described below. In FIG. 21, the operations of blocks otherthan the rate correction data selection means 2104 are entirely the sameas in Embodiment 1. The rate correction data selection means 2104conducts, by using the bit rate error inputted from the bit rate controlmeans 205, rate correction data header inputted from the data separationmeans 207, rate correction data, and normal frame data inputted from thebit amount calculation means 203, the rate control so that the bit rateerror is reduced. A flow of the processing of the rate control is shownin FIG. 22.

[0139] As shown in FIG. 22,

[0140] STEP 1: initially, the positive or negative of the bit rate erroris judged, and when it is negative or zero, the sequence is completed,and when it is positive, that is, bit is excessive,

[0141] STEP 2: the rate correction data header is referred to, and themaximum area of the bit amount is selected.

[0142] STEP 3: to the selected area, the normal frame data is replacedwith the rate correction data,

[0143] STEP 4: after the data is replaced, the bit rate error isrenewed, and the sequence advances to the bit rate error judgementprocess.

[0144] The above processing is repeated until the bit rate error becomesnegative, and when the processing is completed, the frame data isoutputted to the moving picture data combination means. The movingpicture data combination means 208 connects the frame data inputted foreach 1 frame in order, and the moving picture data is produced, andoutputted to the output means 206.

[0145] In the present embodiment, after the rate correction data passesthrough the low pass filter, because it is quantized at the samequantization value as the normal frame, there is only a littledifference in the bit amount, as compared to the normal data which iscoded without low pass filter, and by selecting the rate correction datato a plurality of areas, the fine rate control can be conducted.

[0146] The frequency characteristic of this low pass filter can bedetermined by the user corresponding to the range of the bit ratechange. For example, in the case where the low pass filter having thefrequency characteristic in which the coding data after the passage ofthe low pass filter is 64 kbps, is used to the moving picture data inwhich the bit rate after the coding is 128 kbps, when the input data is128 kbps, the moving picture data in which the fine bit rate change ispossible in the range between 128 kbps and about 64 kbps, can beproduced. Further, the calculation cost which accompanies the bit ratechange is low, and thereby, a plurality of moving picture data whose bitrates are different, can be quickly produced.

[0147] Further, because the difference of the image quality in the ratecorrection data and the normal data are small as compared to the casewhere the image data is produced by changing the quantization value asin Embodiments 1, 2 and 3, the present embodiment is characterized inthat the motion compensation error caused by selecting the ratecorrection data is small.

[0148] As described above, in the present embodiment, to the whole areasin the frame, the moving picture data structure having together the ratecorrection data which is produced by removing the high frequency andbeing coded, and the moving picture coding apparatus by which the ratecorrection data is selected corresponding to the objective bit rate, andthe rate control is conducted, are provided, thereby, because, while themotion compensation error is reduced, the fine rate control can bequickly conducted, a plurality of moving picture data whose bit ratesare different, can be quickly produced, and its practical effect islarge.

[0149] Embodiment 5

[0150] In the fifth embodiment, in the apparatus by which the ratecontrol is conducted from the previously coded moving picture data,without decoding the data, and the moving picture data is newlyproduced, the apparatus characterized in that the input moving picturedata has the data structure in which the bit reduction is possible atthe time of rate control, will be described below. The present apparatusis structured by 2 apparatus of the moving picture data producingapparatus in which the moving picture data is previously coded, and themoving picture coding apparatus in which the rate control is conducted,and the moving picture data is produced.

[0151] Initially, the moving picture data producing apparatus by whichthe moving picture data having the structure in which the bit reductionis possible at the time of rate control, is produced, will be described,and next, the moving picture coding apparatus by which the rate controlis conducted and the moving picture data is produced, will be described.

[0152] In FIG. 6, the structure of the moving picture data producingapparatus is shown. In FIG. 6, a moving picture data producing apparatus601 is provided with: a moving picture coding means 603 connected to aninput means 602; a data dividing position selection means 605 forselecting the dividable position in the data of the Video Packetstructured by continuous arbitrary number of macro blocks; video Packettermination data producing means 606; and rate correction data producingmeans 607 for storing the information for the rate correction, and isprovided with moving picture data combination means 608 connected to theVideo Packet producing means 604 and rate correction data producingmeans 607, and has the structure in which these are connected to anoutput means 609.

[0153] The operation of the moving picture data producing apparatus 601structured as above will be described below. Initially, the input means602 inputs the non-compression image into the moving picture codingmeans 603 for each 1 frame. Then, the moving picture coding means 603conducts the motion compensation, DCT conversion, quantization, andvariable length coding processing on the inputted frame in the VideoPacket unit structured by the continuous arbitrary macro block. Further,the moving picture coding means 603 stores respective start positions ofthe final macro block for each Video Packet at the time of the coding,and produces the Video Packet structure data. The Video Packet structuredata is shown in FIG. 36. In FIG. 36, the Video Packet structure datarecords the total number of the Video Packet, and the start position ofthe final macro block in respective Video Packets.

[0154] Then, the moving picture coding means 603 outputs the coded VideoPacket to the data dividing position selection means 605 and the movingdata combination means 608, and outputs the Video Packet structure datato the data dividing position selection means 605. Herein, the VideoPacket may have the same structure as in the area shown in, for example,FIG. 10, but, it is necessary that each Video Packet is structured bythe continuous macro blocks in the lateral direction.

[0155] The data dividing position selection means 605 selects the areawhich can be deleted at the time of rate control for the respectivefinal macro blocks of the inputted Video Packet, and determines itsborder as the dividing position of the Video Packet. In each VideoPacket, the continuous macro block is accommodated in order, and in eachmacro block, because the variable length sign of the quantized DCTcoefficient is accommodated in order from the low frequency side, in thefinal macro block of the Video Packet, the variable length sign of therear side corresponds to the DCT coefficient of the high frequency.Accordingly, as shown in FIG. 23, the final macro block of the VideoPacket is divided at the time of rate control, and the position todelete the subsequent data is selected from the rear side of the finalmacro block of each Video Packet. That is, the data dividing positionselection means 605 causes the DCT coefficient of the high frequencyaccommodated in rear side of the final macro block of the Video Packetto be the area which can be deleted. Further, because the high frequencycomponent is smaller, as compared to the low frequency component, in theinfluence onto the image quality even when the information is deleted,the deterioration of the image quality by deleting the high frequencycomponent is small. Then, the data dividing position selection means 605outputs the information of the selected position, and its bit amount andthe subsequent to the rate correction data producing means 607, andoutputs the information of the selected position and each Video packetto the Video Packet termination data producing means 606.

[0156] The Video Packet termination data producing means 606 calculates,to the first variable length sign beginning from the position selectedby the data dividing position selection means 605, the variable lengthsign when the sign is the last of the Video Packet, and further, asshown in FIG. 24, produces the Video Packet termination data to whichthe stuffing bit for byte alignment when it is the last of the VideoPacket, is added, and outputs it to the rate correction data producingmeans 607. Herein, the Video Packet termination data itself is alsoadded by the stuffing bit for adjusting the byte alignment. Then, therate correction data producing means 607 collects the divided positioninputted by the data dividing position selection means 605, the bitamounts subsequent to the position, the Video Packet termination datainputted by the Video Packet termination data producing means 606, asthe rate correction data, and output it to the compression frame datacombination means 608. FIG. 25 is a view showing the rate correctiondata structure and rate correction data header structure in the presentfifth embodiment. Further, FIG. 26 is a view showing the data content ofthe rate correction data shown in FIG. 25. The rate correction data hasthe structure, as shown in FIG. 25 and FIG. 26, consisting of the ratecorrection data header, and a plurality of Video Packet terminationdata, and the rate correction data header has the structure includingthe Video Packet number of 1 frame, bit number showing the dividedposition of each Video packet, bit amounts which can be deleted,subsequent to the divided position, and bit amount of the Video Packettermination data.

[0157] Finally, the moving picture data combination means 608 combinesthe normal Video Packet inputted by the Video Packet producing means 604for each 1 frame, and the rate correction data inputted by the ratecorrection data producing means 607 for each 1 frame, in order, andproduces the moving picture data, and outputs it to the output means609.

[0158] Next, the moving picture coding apparatus which conducts the ratecontrol and produces the moving picture data from the moving picturedata produced by the moving picture data producing means, will bedescribed.

[0159] The structure of the moving picture coding apparatus is shown inFIG. 7. In FIG. 7, the moving picture producing apparatus 701 has a ratecorrection data extraction means 703 connected to an input means 702,data composition means 704, and rate correction means 706, and a bitrate control means 705 connected to the input means 702, rate correctiondata extraction means 703, and data composition means 704, and has thestructure connected to an output means 707. The operation of thestructured as described above, will be described below. The movingpicture producing apparatus 701 has the moving picture data outputted bythe output means 609 as an input, and conducts the rate change and newlyproduces the moving picture data.

[0160] The input means 702 inputs the coded moving picture dataincluding the Video Packet for each 1 frame to the rate correction dataextraction means 703, and the objective bit rate into the bit ratecontrol means 705. The rate correction data extraction means 703extracts the rate correction data from the inputted moving picture data,outputs it to the bit rate control means 706, and outputs the normalVideo Packet other than the rate correction data to the data compositionmeans 704. The data composition means 704 combines the inputted VideoPackets and composes the frame data, and outputs the generated bitamount to the bit rate control means 705, and outputs the compositeframe data to the rate correction means 706. Further, the bit rtecontrol means 705 compares the objective bit rate inputted from theinput means 702 to the generated bit amount inputted from the datacomposition means 704, and calculates the bit rate error, and to satisfythe objective bit rate, when the bit amount is excessive, refers to therate correction data header in the rate correction data inputted fromthe rate correction data extraction means 703, and selects from whichposition Video Packet the bit is deleted, and outputs the correctiondata corresponding to the rate correction data header showing theposition, to the rate correction means 706. Herein, the selection methodof the Video Packet to delete the bit, is as follows: the Video Packetis selected in the order of the Video Packet in which the bit amount tobe deleted in the rate correction data header is larger, and the bit isdeleted, and the bit amount which can be deleted, is the differentiatedfrom the bit rate error, and by adding the bit amount of the terminationdata, the bit rate error is renewed, and the selection processing iscontinued until the objective bit rate is satisfied.

[0161] The rate correction means 706 deletes the bits subsequent to thebit position which can be deleted, accommodated in the rate correctiondata header, for the Video Packet inputted by the bit rate control means705, and the Video Packet termination data inputted by the rate controlmeans 706 is inserted instead of them, and the frame data which is ratecorrected, is outputted to the output means 707. The output means 707composes the moving picture data inputted for each 1 frame from the ratecorrection means 706, and produces the moving picture data.

[0162] As described above, to delete the rear portion bit of the finalmacro block of the Video Packet so that rate correction is conducted, isequivalent to that the high frequency component of the final macro blockof the Video Packet is removed, and has the same effect as a case thatthe variable length decoding and re-quantization are conducted, and thebit rate is lowered. Further, because the decoding processing is notnecessary, the processing is light and the rate control can be quicklyconducted.

[0163] Further, the number of the rate correction data is equal to thenumber of the Video Packet, and the number of the Video Packet can beset by the user corresponding to the range of the bit rate change. Forexample, in the case where the size of 1 Video Packet is several % ofthe whole frame, which is small, and the data amount of the rear portionbit which can be deleted, corresponds to about 10% to the data amount of1 Video Packet, when the input data is about 64 kbps, the data in whichthe bit rate can be changed in the range of about 64 kbps to about 56kbps, can be produced. Thereby, in order to cope with the fluctuation ofthe network, the bit rate change can be quickly conducted. Further, thepresent embodiment is characterized in that the rate correction data maybe smaller, as compared to Embodiments 1 to 4.

[0164] As described above, in the present embodiment, the Video Packetstructure whose rear portion bit can be deleted, the moving picture datastructure having the rate correction data in which the positioninformation and termination data are stored, and the moving picturecoding apparatus which refers to the rate correction data and deletesthe bits of rear portion of the Video Packet and conducts the ratecontrol, are provided, thereby, the rate control can be quicklyconducted without decoding the moving picture data, and its practicaleffect is large.

[0165] Embodiment 6

[0166] In the sixth embodiment, in the moving picture coding apparatusin which the rate control is conducted from the previously coded movingpicture data without decoding the data and the moving picture data isnewly produced, the moving picture coding apparatus characterized inthat the input moving picture data has, as the rate correction data, thestructure having the I frame which is the coded image in the frame whosebit amount is different to the normal frame, will be described below.Initially, the moving picture data producing apparatus in which themoving picture data which is an input of the moving picture codingapparatus, is produced, will be described, and next, the moving picturecoding apparatus by which, from the moving picture data coded by themoving picture data producing apparatus, the rate control is conductedwithout decoding the data, and the moving picture data is newlyproduced, will be described below.

[0167] In FIG. 8, the structure of the moving picture data producingapparatus to produce the input moving picture data of the moving picturecoding apparatus is shown. The moving picture data producing apparatus801 is provided with a frame input means 808 connected to the inputmeans 802, P frame coding means 803, and bit amount buffer 804, and isprovided with a frame input means 808, and I frame coding means 805connected to the bit amount buffer 804, and further, is provided with acompression frame data combination means 809 connected to the P framecoding means 803 and I frame coding means 805, and a moving picture datacombination means 806, and has the structure connected to an out putmeans 807.

[0168] The operation of the moving picture data producing meansstructured as described above will be described below. The frame inputmeans 808 inputs the non-compression image into the P frame coding means803 and I frame coding means 805 for each 1 frame. The P frame codingmeans conducts the P frame coding through the motion compensation, DCTconversion, quantization, and variable length coding processing, andoutputs the coded frame to the compression frame data combination means809, and outputs the bit amount of the coded frame to the bit amountbuffer 804. The bit amount buffer 804 outputs the inputted bit amount tothe I frame coding means 805.

[0169] Then, the I frame coding means 805 conducts the I frame codingthrough the DCT conversion, quantization, and variable length codingprocessing, on the frame inputted from the input means 802, and outputsthe coded frame to the compression frame data combination means 809.Herein, the detailed structure of the I frame coding means 805 is shownin FIG. 37. In FIG. 37, the I frame coding means is connected to aninput means 3701, and is structured by a DCT conversion means 3702, DCTcoefficient memory 3703, quantization means 3704, variable length codingmeans 3705, and quantization value determination means 3706, and isconnected to an output means 3707. In FIG. 37, the input means 3701corresponds to the output of the frame input means 808 in FIG. 8, andthe output of the bit amount buffer 804, and inputs the non-compressionframe into the DCT conversion means 3702, and inputs the bit amount intothe quantization value determination means 3706. The DCT conversionmeans 3702 DCT-converts the inputted non-compression data, and outputsit a DCT coefficient memory 3703. The DCT coefficient memory 3703 storesthe inputted DCT coefficient in the internal memory, and inputs the DCTcoefficient into a quantization means 3704. Further, when the DCTcoefficient signal is inputted from the quantization value determinationmeans 3706, the DCT coefficient stored in the internal memory isoutputted to the quantization means 3704. The quantization means 3704conducts the quantization by using the DCT coefficient inputted from thequantizatio coefficient memory, and the quantization value inputted fromthe quantization value determination means, and outputs it to thevariable length coding means 3705. The variable length coding means 3705conducts the variable length coding on the inputted data, and outputsthe variable length coding data and its bit amount to the output means3707, and the outputs the bit amount to the quantization valuedetermination means 3706.

[0170] The quantization value determination means 3706 stores the bitamount inputted from the input means 3701 in the internal memory, andout puts the previously determined quantization value to thequantization means 3704. Further, when the bit amount is inputted fromthe variable length coding means 3705, it is compared to the bit amountstored in the internal memory, and the next quantization value isdetermined so that the bit amount becomes small, and the quantizationvalue is outputted to the quantization means 3704, and the DCTcoefficient output signal is outputted to the DCT coefficient memory3703. Further, by using the bit amount inputted from the variable lengthcoding means 3705, the internal memory is renewed.

[0171] After the above processings are repeated by the number of timesof pieces of the rate correction data which is previously determined bythe user, the quantization value determination means 3706 outputs the Iframe coding end signal to the output means 3707.

[0172] As described above, the I frame coding means 805 produces aplurality of I frames whose bit amount is different from the inputtedbit amount, and outputs the produced I frame and its bit amount to thecompression frame data combination means. Finally, the compression framedata combination means 809 combines the P frame data inputted from the Pframe coding means 803, and the rate correction data produced from aplurality of I frame data and their bit amounts inputted from the Iframe coding means 805, in order, and outputs it to the output means807. FIG. 27 is a view showing the rate correction data structure andthe rate correction data header structure in the present sixthembodiment. Further, FIG. 28 is a view showing the data content of therate correction data shown in FIG. 27. The rate correction data is, asshown in FIG. 27 and FIG. 28, structured by the rate correction dataheader and a plurality of I frames. The rate correction data header hasthe structure in which the number of I frames and respective bit amountsare accommodated in the fixed length.

[0173] Next, the structure of the moving picture coding apparatus inwhich the moving picture data coded by the moving picture data producingapparatus 801 is an input, and the rate control is conducted withoutcoding, and the moving picture data is newly produced, is shown in FIG.9. The moving picture coding apparatus 901 has the structure which isprovided with a rate correction data extraction means connected to aninput means 902 and a bit rate control means 905 connected to the inputmeans 902 and the rate correction data extraction means, and further, arate correction means 906 connected to a bit rate control means 905, andthe rate correction data extraction means 903, and is connected to anoutput means 907.

[0174] The operation of the moving picture coding apparatus structuredas described above, will be described below. The input means 902 inputsthe moving picture data coded by the moving picture data producing means801 for each 1 frame, into the rate correction data extraction means903, and inputs the objective bit rate into the bit rate control means905. The rate correction data extraction means 903 extracts the ratecorrection data from the inputted data and outputs it to the bit ratecontrol means 905, and outputs the normal P frame data other than therate correction data to the rate correction means 906, and outputs thebit amount of the P frame to the bit rate control means 905.

[0175] Then, the bit rate control means 905 compares the objective bitrate inputted from the input means 902, to the bit amount inputted fromthe rate correction data extraction means 903, and when the bit rate issatisfied, and the frame which is preceding 1 frame is notframe-skipped, the control signal in which the rate correction is notnecessary, is outputted to the rate correction means 906. In contrast tothat, when the bit rate is not satisfied, or the frame which ispreceding 1 frame is frame-skipped, the rate correction data header isreferred to, and from I frames in the rate correction data, the I framewhich satisfies the objective bit rate is selected, and the selected Iframe is outputted to the rate correction means 706. Further, even whenthe rate correction data is used, when the bit amount is excessive, theframe skip control signal is outputted to the rate correction means 906,and the information whether the frame skip control signal is emitted, isstored in the internal memory.

[0176] Further, when the control signal of the rate correctionunnecessary is inputted from the bit rate control means 905, the ratecorrection means 906 outputs the frame inputted from the rate correctiondata extraction means 903 as it is, to the output means 907, and whenthe I frame is inputted from the bit rate control means 905, the I frameis outputted to the output means 907, and when the frame skip controlsignal is inputted from the bit rate control means 905, the frame skipcontrol signal is outputted to the output means 907. Finally, the outputmeans 907 collects the frame data inputted from the rate correctionmeans 906 for each 1 frame, and frame skip control signal, and themoving picture data is produced. In this connection, when the frame skipcontrol signal is inputted, the frame is skipped.

[0177] In the present embodiment, because the input moving picture datahas the I frame as the rate correction data, even when the frame skip isconducted at the time of rate control, by using the I frame for the nextframe, the generation of the motion compensation error can be prevented.

[0178] Further, the number of pieces of the I frame which is the ratecorrection data, and the quantization value when the rate correctiondata is produced, can be set by the user corresponding to the range ofthe bit rate change. Foe example, when the quantization of the normalframe data is conducted at the quantization value Q=2, and the bit rateis about 1.6 Mbps, the quantization is conducted by using 2 quantizationvalues of Q=6, Q=29, as the rate correction data, and the data of about384 kbps and about 64 kbps are produced. Then, by using together therate correction data or frame skip, the moving picture data in which thearbitrary bit rate change of range from about 1.6 Mbps to about 64 kbpsis possible, can be produced.

[0179] As described above, in the present embodiment, when the movingpicture data producing apparatus has a means for producing the I framewhose bit amount is different, as the rate correction data, and themoving picture coding apparatus is provided with, as the rate correctiondata, a means for selecting the I frame and conducting the rate control,the rate control can be quickly conducted without decoding the inputmoving picture data, and further, the generation of the motioncompensation error when the frame-skip is conducted, can be prevented,and a plurality of moving picture data whose bit rates are different canbe quickly produced, and its practical effect is large.

[0180] Embodiment 7

[0181] In the seventh embodiment, in an apparatus by which the ratecontrol is conduced from the previously coded moving picture datawithout decoding the data, and the moving picture data is newlyproduced, a moving picture coding apparatus characterized in that aportion of the area in the frame of the moving picture data is quarriedout, and the frame size is different from the input moving picture data,and the moving picture data whose size is the quarried out frame size,is produced, will be described below. When the size is quarried out fromthe frame size of the input image data and the moving picture data isproduced, because the bit rate is not uniform, the bit is not regulateddepending on the quarried out portion, and in order to quarry out, it isnecessary that the bit rate is changed.

[0182] Initially, the moving picture data producing apparatus by whichthe moving picture data which is an input of the moving picture codingapparatus is produced, will be described, and next, the moving picturecoding apparatus by which the rate control is conducted from thepreviously coded moving picture data without decoding the data, and themoving picture data is newly produced, will be described below.

[0183] In FIG. 29, the structure of the moving picture data producingapparatus to produce the input moving picture data of the moving picturecoding apparatus is shown. In FIG. 29, a moving picture data producingapparatus 2901 is provided with: a frame input means 117 connected to aninput means 116; motion compensation means 2902; DCT conversion means103; quantization means 104; variable length coding means 105; inversequantization means 106 to conduct the decoding; inverse DCT conversionmeans 107; and frame memory 108 to store the decoded frame, and isprovided with: a maximum bit amount area detecting means 2910 to detectthe area having the maximum bit amount, connected to the variable lengthcoding means 105; reference inhibition area memory means 109;compression frame buffer 112 connected to the DCT conversion means 103;quantization means 2911 to conduct the quantization, connected to thecompression frame buffer 112; and variable length coding means 2913, andis provided with: a compression frame data combination means 2914 tocombine the moving picture data, connected to the variable length codingmeans 105, reference inhibition area memory means 109, and variablelength coding means 2913, and has the structure connected to the outputmeans 115. The operation of the moving picture data producing apparatusstructured as described above will be described below. In FIG. 29,operations of the motion compensation means 2902, maximum bit amountarea detecting means 2910, quantization means 2911, variable lengthcoding means 2913, and the operation of the blocks other thancompression frame data combination means 2914 are entirely the same asin the Embodiment 1.

[0184] An example of the quarry out area is shown in FIG. 30. In FIG.30, 1 frame is divided into 4 quarry out areas surrounded by a boldline. The moving picture data produced by the moving picture dataproducing means in the present embodiment is different form the inputframe size, and has the structure in which, for example, the movingpicture data can be produced by the moving picture coding apparatus,which will be described later, as the frame size of an arbitrary quarryout area shown in FIG. 30.

[0185] In the Embodiment 1, the maximum bit amount area detecting means110 selects a plurality of areas in the order from the range includingthe maximum bit amount in the plurality of areas in 1 frame shown inFIG. 10, and to the selected area, by changing the quantization value bythe quantization means 111, the rate correction data whose bit amount isdifferent is produced.

[0186] In contrast to that, in the present embodiment, the maximum bitamount area detecting means 2910 selects , for example, as shown in FIG.30, to 1 frame which is divided into a plurality of quarry out areas(rectangular area shown by a bold line), a plurality of areas in theorder from the area in which the bit amount is maximum in each quarryout area, and outputs the selected each area to the reference inhibitionarea memory means 109, and the compression frame buffer 112. In thisconnection, the quarried out area shown in FIG. 30 is an example, andthe quarry out area can be arbitrarily determined. Further, the motioncompensation means 2902 conducts the motion compensation by inhibitingthe motion estimation to the reference inhibition area shown in the ratecorrection data 31 inputted from the reference inhibition area memorymeans and the quarry out area of the position which is different fromthe currently coded quarry area. For example, when the motioncompensation is conducted on the quarry out area 1, the motionestimation is conducted only from the area excepting for the referenceinhibition area in the quarry out area 1, in one preceding frame to theframe into which the input is conducted from the frame memory 108.Tentatively, when the motion estimation is conducted to the outside ofthe quarry area, because there is no reference image to be used for themotion compensation when the area is quarried from the inside of oneframe and the moving picture data is produced, the decoding can not beconducted. As described above, by providing the limitation for themotion estimation, the decoding of the coded moving picture data can beconducted by using not only the whole frame, but also only each quarryarea, and the moving picture data can be structured by quarrying out aportion from the frame of the coded moving picture data.

[0187] The quantization means 2911 changes the quantization value andconducts the quantization by using the DCT coefficient and quantizationvalue of each area selected by the reference inhibition area shown inthe rate correction area data inputted from the compression frame buffer112, that is, selected by the maximum bit amount area detecting means2910, and produces the data whose bit amount is different, andrespectively outputs to the variable length coding means 2913.

[0188] The variable length coding means 2913 conducts the variablelength coding on the DCT coefficient whose bit amount is different, ofeach reference inhibition area inputted by the quantization means 2911,and produces the rate correction data having respective data sizes andarea numbers as the header information, and outputs it to thecompression frame data combination means 114. Herein, the data producedby the variable length coding means 2913 is called the rate correctiondata. In FIG. 33, the structure of the rate correction data is shown. InFIG. 33, the rate correction data header 3302, as shown in FIG. 34, hasthe structure in which the number of the correction data in each area,the area number in the frame, and the bit amounts of respectivecorrection data, are accommodated as the fixed length data. Then, therate correction data has the structure in which the correction data isaccommodated in order succeeding to the rate correction data header3302.

[0189] The compression frame data combination means 2914 links in orderthe normal frame data inputted by the variable length coding means 105,the rate correction area data inputted by the reference inhibition areamemory means 109, and the rate correction data inputted by the variablelength coding means 2913 as shown in FIG. 32, and produces thecompression frame data, and outputs it to the output means 115.

[0190] Next, in FIG. 35, the structure of the moving picture codingapparatus by which a portion in the frame is quarried from the movingpicture data coded by the moving picture coding apparatus in FIG. 29without being coded, and the bit rate adjustment following the quarryingout is conducted, and the moving picture data is newly produced, isshown.

[0191] In FIG. 35, the moving picture coding apparatus 3501 has thestructure which is provided with: a data separation means 3507 connectedto an input means 3502; bit amount calculation means 2303; ratecorrection data selection means 2404; thee bit rate control means 205;and moving picture data combination means 208, and which is connected tothe output means 206. The operation of the moving picture codingapparatus structure as described above will be described below. In FIG.35, the operations of blocks other than the input means 3502 and dataseparation means 3507, are entirely the same as in Embodiment

[0192] The input means 3502 inputs the moving picture data which iscompression coded by the moving picture data producing means 2901,objective bit rate, quarry area information showing the quarry outmethod of 1 frame as shown in FIG. 30, and quarry out area numbershowing which portion of the input data is to be quarried out, to thedata separation means 207. When the data is inputted into the dataseparation means 3507 by the input means 3502, the objective bit rate isinputted into the bit rate control means 205 for each 1 frame, and thedata is taken out in order from the leading end of the inputted movingpicture data, the quarrying out and composition is conducted on thenormal frame data corresponding to the quarry out area number, and it isinputted into the bit amount calculation means 203 for each 1 frame, andthe rate correction data corresponding to the rate correction area dataand the quarry out area number is inputted into the rate correction dataselection means 204.

[0193] Generally, in the case where, to the previously coded image data,a portion of the frame is quarried out and the new moving picture datawhose frame size is different, is produced, when the motion estimationis conducted from the area other than the area in which the previouslycoded image data is quarried out, the problem in which it can not bedecoded, is generated. That is for the reason why the necessaryreference data to decode the quarried out area does not exist inside thequarried out area. That is, because the necessary reference data existsoutside the quarried out area, it is impossible that the quarrying outis simply conducted, and in order to quarry out a portion of the frameand produce the new moving picture data whose frame size is different,it is necessary that, after whole frame is decoded once, the inside ofthe quarry out area is coded again, and there is a problem that theprocessing load is large.

[0194] In contrast to that, in the present embodiment, when the dataseparation means 3507 quarries out the data of the area shown by thequarry out area number from the normal frame data, and composes the newframe whose frame size is different, because the motion estimation ofthe quarried area is conducted only in the same area, there is no casethat the motion compensation error is generated by the quarrying out,and it can not be decoded. Accordingly, it can be quarried out andcomposed without decoding the data. Further, also the change of bit ratefollowing the quarrying out, can be conducted without decoding the databy selecting the rate correction data by adjusting to the objective bitrate in the same manner as in Example 1.

[0195] Further, the number of areas having the rate correction data andthe rate correction data of each area can be set by the usercorresponding to the range of the bit rate change, and has the sameeffect as in Embodiment 1, however, the rate correction data necessaryonly for conducting the bit rate adjustment following the quarrying outmay be small. For example, when the quarry out areas are 4 and thequantization value of the normal frame data Q=8, and the bit rate isabout 256 kbps, as the rate correction data, at least one area in whichthe bit amount is large is selected in respective quarry out areas, andwhen the rate correction data of about 96 kbps (as the whole frame) inwhich the quantization is conducted by using the quantization valueQ=20, is produced, it is sufficiently enough for adjustment of the bitrate generated following the quarry out. That is, when the quarry outareas is 4, and the bit rate is about 256 kbps, it is necessary that thebit rate of the frame quarried out by the quarry out of the area is ¼ ofthe whole, that is, about 64 kbps, however, in practice, by thedeviation of the bit amount, the area over 64 kbps exists. In thepresent embodiment, the rate correction data is produced, and by usingthe rate correction data at the time of quarry out of the area, the bitrate of such the area can be adjusted.

[0196] As described above, in the present embodiment, the moving picturedata structure having the area having the rate correction data in whichthe bit amount is different for each quarry area, a means by which thearea of a portion in the frame is quarried out and composed, and an areaselection means for selecting the rate correction data corresponding tothe bit rate, are provided, thereby, a portion of the frame is quicklyquarried out without decoding the moving picture data, and withoutgenerating the deterioration of image quality, and further, the bit rateadjustment can be conducted and the new moving picture data whose framesize is different, can be produced, and its practical effect is large.

[0197] Further, in the present embodiment, when a point that the areahaving the reference inhibition area and rate correction data isproduced in 1 frame, is changed to that it is produced for each quarryout area, and following that, also for the motion compensation, themotion estimation is not conducted from the outside of the quarry outarea, it is shown that the effect in which, not only by conducting therate control without decoding the coded moving picture data, but also byquarrying out a portion in the frame without decoding the data, themoving picture data whose frame size is different can be produced, canbe obtained, and for Embodiment 2 to Embodiment 6, by conducting thesame change, a portion in the frame is quarried out, and the movingpicture data can be produced.

[0198] Further, in Embodiments 1 to 7, it is described that the movingpicture data producing apparatus accommodates the rate correction dataafter the normal frame date, however, the position to be accommodated,is not limited to this. For example, when the moving picture dataproducing apparatus accommodates the rate correction data after the userdata start sign in the moving picture data, the data can be reproducedby using the normal moving picture decoding apparatus.

[0199] Herein, the user data start sign is, for example, as shown inISO/IEC 11172-2 which is the standard book of MPEG coding, a signshowing the start of the area which is prepared for the futureexpansion, and the normal moving picture decoding apparatus skips overthe data from the user data start sign to the next start sign andconducts the decoding. Accordingly, the moving picture data produced bythe moving picture data producing apparatus in Embodiments 1 to 7, canbe reproduced by using the normal moving picture decoding apparatus.

[0200] Further, in the present invention, the input data of the movingpicture coding apparatus and output data are compared with each other,or a plurality of output data whose bit rates are different, arecompared, and when bit arrangement is locally different, it isstructured in such a manner that the bit arrangement is accommodated inthe user data, or position other than the normal frame data.

[0201] Further, when the monochrome frame is an input, each frame of themoving picture data outputted by the moving picture data producingapparatus has the periodic structure in which, other than normal framedata, as the rate correction data, the entirely same data areperiodically included by the number of areas between the areas, andbecause the entirely the same rate correction data is also includedbetween the frames, the moving picture data has the periodic structure.

[0202] As described above, firstly, when the moving picture data has thestructure having the rate correction data whose bit amount is different,to the area in which the bit amount in the P frame (predictive codingimage between frames) is large, in the case where the moving picturedata is newly produced from the previously coded moving picture data, byselecting the data whose bit amount is different, corresponding to theobjective bit rate, the bit rate can be changed without decoding themoving picture data, and the moving picture data can be quicklyproduced.

[0203] Secondly, in the case where the moving picture data has the ratecorrection data in which the bit amount is different, and the ratechange can be conducted, on the predetermined area in which theprobability referred to at the time of the motion estimation from thenext frame is low in the P frame (predictive coding image betweenframes), and the moving picture data is newly produced from thepreviously coded moving picture data, by selecting one data from ratecorrection data whose bit amount is different, in the input movingpicture data, corresponding to the objective bit rate, the bit rate canbe changed without decoding the moving picture data, and the movingpicture data can be quickly produced. Further, by producing the ratecorrection data in the area in which the probability referred to fromthe next frame is low, the lowering of the predictive coding efficiencydue to the influence of the search area limitation of the motionestimation, can be reduced.

[0204] Thirdly, in the moving picture data producing apparatus, byproviding the motion compensation means for inhibiting the reference, atthe time of the motion estimation of the next frame, to the area havingthe rate correction data in the P frame of the moving picture data toconduct the coding, when the moving picture data is newly produced fromthe coded moving picture data, even by selecting the rate correctiondata whose bit amount is different, corresponding to the objective bitrate, the generation of the motion compensation error due to the changeof the data can be prevented.

[0205] Fourthly, in the moving picture data producing apparatus, whenthe P frame of the moving picture data is produced, to the area in whichthe referred degree data showing the area in the preceding frame usedfor reference at the time of motion estimation is recorded, and by usingthe referred area data, which is selected as the area that the referreddegree is low, by providing the means for producing the rate correctiondata whose bit amount is different, the moving picture coding can beconducted without lowering the coding efficiency of the predictivecoding between frames. Further, when the moving picture data is newlyproduced from the previously coded moving picture data, by selecting thedata whose bit amount is different, corresponding to the objective bitrate, the bit rate can be quickly changed without decoding the data, andthe moving picture data can be produced.

[0206] Fifthly, in the moving picture data producing apparatus, byproviding the means for producing the data in which the predictivecoding between frames is conducted on the original image to the P frameof the moving picture data, and the means by which the high frequencycomponent of the original image is removed, and by conducting thepredictive coding between frames, the rate correction data whose bitamount is different, is produced, when the moving picture data is newlyproduced without decoding the coded moving picture data, by selecting aplurality of areas in the rate correction data, in which the highfrequency component is removed and coded, and bit amounts are different,the fine bit rate control can be quickly conducted.

[0207] Sixthly, in the moving picture data producing apparatus, byproviding the means for producing the position at which the subsequentbit can be deleted, and the termination data to each Video Packet of themoving picture data, in the moving picture coding apparatus by which thenew moving picture data is produced from the coded moving picture datais produced, by selecting the Video Packet corresponding to theobjective bit rate, and by deleting the rear portion bits, the bit ratecontrol can be quickly conducted.

[0208] Seventhly, in the moving picture data producing apparatus, in thecase where the means for producing a plurality of I frames whose bitamounts are different, as the rate correction data, to the P frame ofthe moving picture data, is provided, when the moving picture data isnewly produced from the previously coded moving picture data, byselecting or frame skipping the rate correction data corresponding tothe objective bit rate, the bit rate control can be quickly conducted,and the moving picture data can be produced.

[0209] Eighthly, in the case where the structure in which an area havingtogether the rate correction data whose bit amount is different in the Pframe (predictive coding image between frames) of the moving picturedata is provided at least one for each quarry out area determined in theframe is provided, and the moving picture data producing means isprovided with the motion compensation means in which the motionestimation is not conducted from the different quarry out area and thearea having the rate correction data, when one portion in the frame isquarried out from the previously coded moving picture data and themoving picture data is newly produced, by selecting the data whose bitamount is different, corresponding to the objective bit rate, the bitrate can be controlled without decoding the moving picture data, andwithout generating the motion compensation error, and the moving picturedata can be quickly produced.

What is claimed is:
 1. A moving picture data producing apparatus towhich non-compression moving picture data is input, comprising:quantization means; and rate correction data producing means forproducing rate correction data which is used at a time of bit ratechange, whereby moving picture data having the rate correction dataother than normal moving picture stream is produced.
 2. A moving picturedata producing apparatus according to claim 1, wherein said ratecorrection data producing means conducts quantization different fromsaid quantization means on an area in which the bit generation amount ineach frame of the moving picture data is large, and the rate correctiondata by which the rate change is possible, is produced.
 3. A movingpicture data producing apparatus according to claim 1, wherein said ratecorrection data producing means, in a P frame of the moving picturedata, conducts the quantization different from the quantization means onan area in which the provability referred at the time of the motionestimation time is low, and the rate correction data in which the ratechange is possible, is produced.
 4. A moving picture data producingapparatus according to anyone of claims 1 to 3, further comprising meansfor recording reference inhibition area information which shows an areahaving the rate correction data in each frame of the moving picturedata; and motion compensation means for conducting motion compensation,wherein, when motion estimation in the next frame is performed, an areashown by the reference inhibition area information shows is inhibitedfrom referring.
 5. A moving picture data producing apparatus accordingto claim 1, further comprising: motion compensation means for conductingmotion compensation and outputting the referenced area informationreferred to at the time of the motion estimation; and wherein said ratecorrection data producing means uses the referenced area information andselects the area in which the referenced degree is low in the frame, sothat the rate correction data by which the rate change is possible withrespect to the selected area is produced.
 6. A moving picture dataproducing apparatus according to claim 1, wherein said rate correctiondata producing means deletes high frequency components from an originalimage and conducts the same quantization as said quantization means, andproduces the rate correction data by which the rate change is possible.7. A moving picture data producing apparatus according to claim 1,wherein said rate correction data producing means decides a position atwhich rear portion bits can be deleted, with respect to area structuredby a continuous arbitrary number of macro-blocks (for example, 16×16pixels), and produces the rate correction data in which the positioninformation is recorded, by which the rate change is possible.
 8. Amoving picture data producing apparatus according to claim 1, whereinsaid rate correction data producing means produces an I frame which is acoding image inside the frame, and produces the rate correction data bywhich the rate change is possible.
 9. A moving picture data producingapparatus to which non-compression moving picture data is input,comprising: quantization means; rate correction data producing means forproducing the rate correction data which is the data used when the bitrate is changed; and means for deciding a quarry out area by quarryingout a part of a frame to able to decoding, whereby moving picture datahaving the rate correction data other than normal moving picture streamis produced.
 10. A moving picture data producing apparatus according toclaim 9, wherein the rate correction data producing means produces therate correction data which the rate change is possible, to at least oneof areas in respective quarry out areas in each frame.
 11. A movingpicture data producing apparatus according to claim 9, furthercomprising motion compensation means for conducting a motioncompensation, in which it is inhibited to refer an area having the ratecorrection data in the preceding frame and to a different quarry outarea to conduct motion estimation.
 12. A moving picture coding apparatusfor producing and outputting moving picture data whose bit rate isdifferent from input moving picture data which is previously compressioncoded, said apparatus comprising: bit rate correction means by which thebit rate is changed by referring to rate correction data contained insaid input moving picture data, whereby the bit rate is changed whilethe input moving picture data is not decoded.
 13. A moving picturecoding apparatus according to claim 12, wherein said bit rate correctionmeans uses the rate correction data whose bit amount is different,included in the inputted moving picture data, and by replacing thepreviously coded moving picture data, corresponding to the objective bitrate, the bit rate change is conducted.
 14. A moving picture codingapparatus according to claim 12, wherein said bit rate correction meansselects an area in which the bit can be deleted, shown in the ratecorrection data included in the input moving picture data correspondingto the objective bit rate, and by deleting the bit, the bit rate changeis conducted.